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Hi - On Thu, Apr 14, 2005 at 02:05:29PM -0700, Jim Keniston wrote: > [...] > > Please be more specific. Having implicitly declared and typed > > systemtap variables poses a crash risk to the kernel how? > > probe s; // array of pointers to structs > j = -1; > ... > jj = what_j_should_be; // misspelled "j" as "jj" > ... s[j]->foo ... > > This gives you at least a stray memory reference. That would at worst yield some garbage. > If it's an assignment to s[j]->foo, it scribbles on God-knows-what. It is obvious that any assignment like this, if at all supported, would be a guru-mode-only operation. Can you please spell out how this relates to implicitly typed/declared variables? How might the same mistake not be made in C? > > [...] Can you provide motivation for each > > of these constructs as really useful/necessary to a systemtap user? > > They clearly toss the barn door wide open. > > Yes, I'm sure I could, but I think we agree that it would more > useful to create real-world instrumentation and see which features > we need. [so let's build it and see if it is needed]. Er, ok, if such an experiment were of disposably low cost, I wouldn't stand in its way. But really we ought to be able to do at least a bit of thought-experimenting before coding. - FChE
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